Air cooled shuttle clutch transmission

ABSTRACT

A cooling arrangement for a V-belt clutching and reversing transmission including a central pulley section flanked by pulleys on either side and wherein said flanking pulleys are provided with fan elements for moving air axially towards said central pulley section and the latter is provided with ribs for moving such air radially outward toward the periphery of said central pulley section for cooling such central pulley section, such flanking pulleys and the V-belts connected therewith.

United States Patent [191 Freier, Jr.

451 Feb. 5, 1974 AIR COOLED SHUTTLE CLUTCH TRANSMISSION [75] Inventor:Edward Freier, Jr., Port Washington, Wis.

[73] Assignee: Simplicity Manufacturing Company,

Inc., Port Washington, Wis.

[22] Filed: Nov. 7, 1972 [21] Appl. No.: 304,498

[52] US. Cl 74/230.l7 D [51] Int. Cl. Fl6h 55/22 [58] Field of Search.74/230.17 B, 230.17 D, 230.6;

[5 6] References Cited UNITED STATES PATENTS 3,628,390 12/1971 Van DerLely et al 74/230.l7 D

FOREIGN PATENTS OR APPLICATIONS Canada 74/2306 829,536 1/1952 GermanyPrimary Examiner-Leonard H. Gerin Attorney, Agent, or Firm-Charles L.Schwab ABSTRACT A cooling arrangement for a V-belt clutching andreversing transmission including a central pulley section flanked bypulleys on either side and wherein said flanking pulleys are providedwith fan elements for moving air axially towards said central pulleysection and the latter is provided with ribs for moving such airradially outward toward the periphery of said central pulley section forcooling such central pulley section, such flanking pulleys and theV-belts connected therewith.

1 Claim, 9 Drawing Figures Patented Feb 5, 1974 6 Sheets-Sheet 1Patented Feb. 5, 1974 6 Sheets-Sheet 2 Patented Feb. 5, 1974 v 3,789,684

6 Sheets-Sheet 5 Patented Feb. 5, 1974 3,789,684

6 Sheets-Sheet 4 AIR COOLED SHUTTLE CLUTCH TRANSMISSION This inventionis concerned with a cooling system for a V-belt transmission fordissipating heat generated therein.

An object of this invention is to provide a simple V- belt transmissionproviding forward and reverse speeds and wherein the pulleys used insuch transmission are provided with fan and rib elements for moving airin a desired direction to cool such pulleys and V-belts connectedthereto.

A further object of this invention is to provide a simple V-belttransmission providing forward, reverse and neutral positions andwherein such transmission includes a central pulley section flanked byadjacent pulleys on either side and wherein such adjacent pulleys areprovided with fan elements for moving air towards such central pulleysection and the latter is provided with rib elements for moving such airradially outwards to cool the pulleys and V-belts forming such transmis-SlOn.

These and other objects will become apparent to those skilled in the artfrom the following description taken in conjunction with the attacheddrawings, in which:

FIG. 1 is a side elevation view of a riding lawnmower incorporatingfeatures of the present invention;

FIG. 2 is a view taken on line Il-II of FIG. 1;

F IG. 3 is a perspective view of the mower blade drive with partsremoved for clarity of illustration;

FIG. 4 is a perspective view of the mower belt transmission drive withparts removed for clarity of illustration;

FIG. 5 is an enlarged top elevation view in section through thetransmission;

F IG. 6 is a diagrammatic side elevation view of the controls of themower transmission;

FIG. 7 is a plan view of FIG. 6;

FIG. 8 is a section view taken on line VIII-VIII of FIG. 5; and

FIG. 9 is a section view taken on line IXIX of FIG.

Referring to FIGS. 1 and 2, a self-propelled lawnmower 10, incorporatingfeatures of the present invention is seen including a chassis 11, arotary mower attachment 12, a power transmission 13, and an engine 14.Chassis 11 provides a horizontal platform 16 for supporting the engine14 and the transmission 13. The chassis 11 includes a pair of sidewallsl7 and 18 which are supported transversely spaced apart by a rear axlestructure 19 including suitable reduction gearing enclosed in housing21.

Engine 14 is provided with a depending drive shaft 22 to whichare-attached drive pulleys 23 and 24. Drive pulley 23 is connected bymeans of V-belt 26 with driven pulley 27 for driving mower attachment12. A pair of pulleys 28 and 29 (FIG. 3) are mounted for rotation aboutbolts 31 which are carried by depending arms 32 and 33 of invertedU-member 34 which is pivotally attached to pin 35 pivotally connected tochassis 11 for movement about a transverse axis. V-belt 26 passes aboutpulleys 28 and 29 which tension such belt to provide a drivingconnection between engine 14 and driven pulley 27 of rotary mowerattachment 12. Conventional operator controlled toggle means (not shown)are provided for retaining pulleys 28 and 29 in belt tightening relationto V-belt 26 or in belt relaxing relation.

Drive pulley 24 (FIG. 4) is connected by V-belt 36 to idler pulley 37which is adjustably spring-mounted from structural member 38 (FIG. 1)attached between sidewalls 17 and 18 by cross member 40. Between drivepulley 24 and idler pulley 37 belt 36 passes halfway around a clutch andtransmission mechanism 39 which is mounted about an input shaft 41rotatably supported in housing 21 (FIG. 5). A central half-pulley member42 (see FIGS. 4 and 5) is keyed to shaft 41. Pulleys 43 and 44 aremounted on shaft 41 for rotation relative thereto and are positionedadjacent to half-pulley section 42. Pulley 43 is provided with a surface46 adjacent to the periphery thereof which with surface 47 onhalf-pulley section 42 forms a seat for a V-belt 48 which is mountedabout idler pulley 49 (FIG. 4) rotatably carried by one leg 51 of aU-bracket 52 attached to a crank 53 pivotally supported in sidewalls 17and 18 (FIG. 2). Pulley 44 (FIG. 5) is provided with a surface 54adjacent to the periphery thereof which with surface 56 of half-pulleysection 42 forms a seat for a V-belt 57 which is mounted about idlerpulley 58 (FIG. 4) rotatably carried by the other leg 59 of U-bracket52. It is to be noted that pulleys 49 and 58 are mounted at differentheights on U-bracket 52 so that as crank 53 is turned pulleys 49 and 58will be moved toward or away from shaft 41 alternately. In other words,when crank 53 is positioned with pulleys 49 and 58 equidistant fromshaft 41, this is a neutral position and neither belt 48 nor 57 willcause a driving connection between pulleys 49 or 58 with half-pulleysection 42. As crank 53 is pivoted clockwise as viewed in FIG. 4 a belttightening relation is established between pulley 58 and halfpulleysection 42 through V-belt 57 so that belt 36 drives half-pulley section42 and thereby shaft 41 and the connected transmission 13 in a forwardlydirection. If crank 53 is pivoted counterclockwise as viewed in FIG. 4 abelt tightening relationship is established between pulley 43 andhalf-pulley section 42 resulting in half-pulley 42 being driven by belt36 in a direction opposite to which it previously was driven and thisresults in shaft 41 and transmission 13 being driven a reversedirection.

A foot pedal 59 is pivotally mounted on pin 61 carried by chassis 11(see FIGS. 1, 2, 6 and 7). A rod 62 has one turned-over end 63 pivotallyreceived in pedal 59. The other end of rod 62 passes through a U-shapedmember 64 and has that end thereof threaded to receive nut 66. Acompression spring 67 is interposed between nut 66 and U-shaped member64 in biasing relation to said latter member. Member 64 is pivotallyattached to the upper end of strap which is attached at a midportionthereof to crank 53 for movement therewith. A rod 68 (FIG. 6) has aforward end thereof attached at as by welding to a midportion of rod 62and the rearward end of rod 68 passes through openings in a rod guide 69pivotally attached to lower end of strap 65. The rearward end of rod 68is threaded to receive a nut 71. A compression spring 72 is interposedbetween nut 71 and rod guide 69 about rod 68 in biasing relation toguide 69.

In other words, when the operator steps down on the foot pedal 59 thisexerts a pull on rod 62 compressing either spring 67 or 72 or both andthus moving strap 65, crank 53 and shifting'pulleys 49 and 58 to theneutral position shown in FIG. ltw-herein neither pulley 49 nor 58 istightening belt 48 or 57 to establish a driving relation withhalf-pulley 42 for providing a drive from belt 36 to shaft 41 and itsconnected transmission 13.

Also pivotally received in foot pedal 59 (FIGS. 6 and 7) is turned-overportion 73 of rod 74. The other end of rod 74 passes through aturned-over end portion 72 of Z-bar 77 and is threaded to receive a nut78. A spring 79 is interposed about rod 74 between portion 76 and nut78. Z-bar 77 is attached to one end of brake band 81 which has its otherend connected to pin 82 carried by transmission housing 21. Brake band81 surrounds a brake disc 83 keyed to brake shaft 84 forming a part ofpower transmission 13 as will be later described.

A forward, reverse and neutral shift is provided by movement of handlever 86 which is pivoted for movement about shaft 87 pivotally carriedby chassis 11. Hand lever 86 is provided with a coacting quadrant member88 (FIG. 1) also attached to chassis 11 which quadrant member providesconventional means (not shown) for retaining lever 86 in any desiredadjusted position. As shown, lever 86 is in a neutral position, if movedforwardly lever 86 would be in a forward drive position and if movedrearwardly lever 86 would be in a reverse drive position.

Lever 86 is provided with a depending portion 89 which pivotallyreceives a turned-over end portion 91 of rod 92. The other end of rod 92is slideably received in rod guide 93 which pivotally attaches to alower portion of strap 65. Rod 92 is provided with a set collar 94attached thereto between the legs 96 and 97 (FIG. 1) of rod guide 93.Springs 98 and 99 are mounted about rod 92 and positioned between leg 96and collar 94 and between leg 97 and collar 94, respectively, so that ifthe operator wishes to run the mower forwardly, he moves lever 86forwardly. This results in depending portion 89 moving rearwardly. Thisrearward movement of portion 89 moves rod 92 rearwardly compressingspring 98 against leg 96 until crank 53 is moved clockwise as viewed inFIG. 4 causing a tightening of belt 57 and thereby establishing adriving relation between pulley 44 and half-pulley 42 driving shaft 41in a forward direction. If the operator wishes to run the mowerrearwardly, he moves lever 86 rearwardly, this results in dependingportion 89 moving forwardly. This forward movement of portion 89 movesrod 92 and compresses spring 99 against leg 97 until crank 53 is movedcounterclockwise as viewed in FIG. 4 causing a tightening of belt 48 andthereby establishing a driving relation between pulley 43 andhalf-pulley 42 in a rearward direction driving shaft 41 in a rearwarddirection and such rotation of shaft 41 causes mower to move in areverse direction.

If lever 86 is moved to the central or neutral position this moves rod92 to the position shown in FIG. 1 wherein both springs 98 and 99 arebiasing collar 94 and crank 53 to the neutral position shown whereinneither belt 48 nor belt 57 is tightened so that no driving connectionbetween either pulley 43 or 44 is secured with half-pulley 42.

Also mounted for movement about shaft 87 is the parking brake lever 101which is provided with a strap 102 attached thereto and which strappivotally receives one end of a turned-over portion 103 of rod 104. Theother end of rod 104 passes through an opening in turned-over portion106 of Z-bar 77. This other end of rod 104 is threaded to receive a nut107. A spring 108 is positioned about rod 104 between nut 107 andturned-over portion 106. Brake lever 101 is toggle mounted relative toshaft 87 so that when brake lever 101 is depressed sufficiently to moveturned-over portion 106 over center, this results in a pull-on Z-bar 77and the aforesaid toggle arrangement maintains Z-bar 77 applying atightening of brake band 81 about brake disc 83.

Shift mechanism (FIGS. 1 and 5), generally designated 109, is operatedby a manually actuatable gear shift lever 111 readily accessible to anoperator occupying seat 112, provides for sliding a compound gear 113 onsplines of the input shaft 41 back and forth to selectably mesh its highand low sections 114, 116 respectively with the second and first speedgears 117, 118 on the brake shaft 84. Thus low speed propulsion of themower 10 results when the compound forward gear is shifted to the rightof neutral to bring the low speed gear 116 into mesh with the firstspeed gear 118. Similarly, high speed propulsion is effected by shiftingthe compound gear to the left of neutral to bring the high speed gear114 thereof into mesh with second speed gear 117 on the brake shaft 84.

The differential transmission is of the spur gear type and includes amain gear 119 meshing with a gear 121 connecting gears 117 and 118. Maingear 119 is rotatable about the common axis of the axle shafts 122, 123,both with and with respect thereto. Gear means designated generally bythe reference numeral 124 includes planetary gearing including a pair ofspur gears 126 and 127 respectively fixed to the shafts 122 and 123, andtwo pairs of planet gears 128 and 129. One of the planet gears of eachpair meshes with one of the spur gears and the other of each pair ofplanet gears meshes with the other spur gear. In addition, the planetgears mesh with one another, for which purpose the planet gears arewider than the spur gears.

All of the planet gears are carried by the main gear 119 being journaledon sleeves 131 that are slipped onto tie bolts 132 by which the maingear 119 and a disc 133 are connected in spaced coaxial relationshiptherewith, the sleeves 13] serving to space the disc from the main gear.The main gear together with the discs 133 and the tie bolts connectingthem thus constitute a power input means through which the transmissionis connected to a power source. The structure described constitutes aconventional differential transmission.

As to the operation of the mower with control lever and shift lever 111with both in neutral position, the engine 14 is started. Parking brake101 is released and shift lever 111 is moved into either low or highgear while control lever 86 is moved into forward position which movespulley 58 on crank 53 into belt-tightening relationship with V-belt 57.One side of V-belt 57 contacts surface 54 of transmission pulley 44 andthe opposite side of V-belt 57 contacts surface 56 of discclutch 42causing disc-clutch 42 to be driven by belt 36 through this frictionalcontact. Disc-clutch 42 is keyed to shaft 41 and moves the mower in aforward direction of travel. To reverse the direction of mower travel,control 86 is pulled to reverse position which moves pulley 58 on crank53 out of belt-tightening relation with V- belt 57 and therebyinterrupting the drive existing between pulley 44 and disc-clutch 42 andmoves pulley 49 into belt-tightening relation to V-belt 48 which on oneside moves into frictional engagement with side 47 of disc-clutch 42 andwith side 46 of pulley 43 which is rotating in a clockwise directionfrom being driven by another portion of belt 36 and thus the mower movesin a reverse direction.

With control lever 86 engaged to provide travel in either direction, andfoot pedal 59 depressed crank 53 returns pulleys 49 and 58 to neutralposition. With the release of foot pedal 59, pulleys 49 and 58 return tothe position they were previously placed in by control lever 86 and thusit is seen that foot pedal 59 can be used as a conventional clutch forcontrolling the ground traversing movement of the mower.

No matter what position lever 86 is positioned in, whether in forward,reverse or neutral when foot pedal 59 is stepped down on, simultaneouslybrake rod 74 applies a pull on Z-bar 77 tightening brake band 81 aboutbrake disc 83 and thereby braking shaft 84 in the connected transmission13; while also shifting pulleys 49 and 58 to the neutral position shownin FIG. 1. Whatever position 86 is positioned in, forward, reverse orneutral then when foot pedal 59 is released, pulleys 49 and 58 return tothe positions they were in prior to foot pedal 59 being stepped down on.

lt is to be noted thatthis forward and reverse speed belt transmissioncombined with the shown two-speed gear shift transmission provides acombination transmission having two forward and two reverse speeds.

Referring to FIGS. 5, 8 and 9, it is seen that pulleys 43 and 44 areprovided with fan blade elements 136 and 137, respectively, incorporatedin the webs 138 and 139 thereof and which blade elements are designed tomove air axially as pulleys 43 and 44 rotate. Fan blade element 136moves air axially through opening 141 in web 138 towards the right asviewed in FIG. 5 and fan blade element 137 moves air axially throughopening 142 in web 139 towards the left. Half-pulley or disc-clutch 42is provided with rib elements 143 and 144 incorporated in the web 146thereof which rib or blade elements are designed to move air radiallyoutwardly so that the paths taken by air moved by blade elements 136,137, 143 and 144 are shown by arrows in FIG. 5 and this movement of airproduces a cooling effect on the pulleys 42, 43 and 44 and on theV-belts connected thereto. The air moved by fan blade elements 136 and137 moves axially in opposite directions towards half-pulley 42 andthese two air streams infringe on half-pulley 42 whose fan elements 143and 144 pick up these impinging air streams and moves same radiallyoutwardly to provide a cooling circulation of air for the pulleys andbelts forming the trans mission.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. In a V-belt transmission and reversing mechanism having a pair ofspaced apart pulleys mounted on a shaft, a central half-pulley sectionattached to said shaft between said pulleys and closely adjacent to eachof said pulleys, each of said pair of pulleys being provided with ahalf-pulley section coacting with said central half-pulley section toprovide a pulley for receiving a V-belt positionable for drivenlyconnecting said central half-pulley section to one of said pair ofpulleys, the improvement comprising heat dissipating means for saidmechanism and wherein each of said pair of pulleys is provided with afan blade incorporated in the webs thereof for moving air axially towardsaid central halfpulley section, and said central half-pulley section isprovided with a solid web for intercepting the axially moving air andsaid solid web is provided with radially extending blades for changingthe direction of the axially moving air to a radial outward directiontoward said belt and the outer surfaces of said pulleys and said centralhalf-pulley section.

1. In a V-belt transmission and reversing mechanism having a pair of spaced apart pulleys mounted on a shaft, a central halfpulley section attached to said shaft between said pulleys and closely adjacent to each of said pulleys, each of said pair of pulleys being provided with a half-pulley section coacting with said central half-pulley section to provide a pulley for receiving a V-belt positionable for drivenly connecting said central half-pulley section to one of said pair of pulleys, the improvement comprising heat dissipating means for said mechanism and wherein each of said pair of pulleys is provided with a fan blade incorporated in the webs thereof for moving air axially toward said central half-pulley section, and said central halfpulley section is provided with a solid web for intercepting the axially moving air and said solid web is provided with radially extending blades for changing the direction of the axially moving air to a radial outward direction toward said belt and the outer surfaces of said pulleys and said central half-pulley section. 